I use screen almost by default when connecting over SSH, but I've never used -x and didn't know about it.
Habbit from back in the dial-up days when connections got dropped quite frequently. Still relevant with laptop going into sleep mode and such.
So nice to just resume wherever you were as of nothing happened. Or to run jobs in the background, like long compiles, without an additional SSH session.
The risk is anything else dropping your connection while an interactive long-running process is going. You can nohup, or run inside something like screen/tmux,
You're not wrong, but largely in the virtualized world we live in, it matters less and less when you have a virtual console.
That said the sshd session you are connected on is still running the old executable until the service is restarted AND your session ends, so even if sshd gets upgraded, you should still be good to go.